Project Report. California Department of Fish and Game. October 2010

Transcription

1 Areas of Conservation Emphasis (ACE-II) Project Report California Department of Fish and Game October 2010 ACE-II Technical Team: Melanie Gogol-Prokurat, Monica Parisi, Adrienne Truex, Eric Haney, Dan Applebee, Ray McDowell, L. Guphy Gustafson, Kristi Fien, Rod Gonzalez, Kevin Shaffer, Julie Horenstein, Dave Dixon ACE-II Steering Committee: Tina Bartlett, Armand Gonzales, Kevin Hunting, Tom Lupo, Sandra Morey, Amber Pairis, Kevin Shaffer ACE-II GIS Development: Dean Chiang, Steve Goldman, Michael Dangermond

2 Table of Contents Executive Summary... 4 Background... 6 The Role of ACE-II in Conservation Prioritization... 6 Project Goals and Assumptions... 7 Department Planning and Conservation Prioritization Goals... 7 Assumptions... 8 ACE-II Objectives... 8 ACE-II Data Layer Descriptions, Uses and Limitations... 9 Hexagons... 9 Data precision... 9 Biological Datasets Native Species Richness Rare Species Richness Rarity-weighted Richness Sensitive Habitats Riparian Wetland Rare Natural Communities High Value Salmonid Habitat Biological Index Recreational Datasets Harvest Species Richness Hunting Demand Deer Tag Demand Waterfowl Hunt Demand Recreational Access Percent Huntable Public Lands Fishing Opportunity Locations Wildlife Viewing Opportunity Locations Hunting Use Landscape Considerations Current level of protection Habitat Connectivity Stressors Urban Footprint ACE-II Development Data Sources Call for Data Criteria for Inclusion of Data Layers Unit of Analysis, Scale and Extent Choosing a Unit of Analysis Scale Extent of Analysis Statewide Extent ACE-II Project Report 2

3 Ecoregional Extent Species and Habitat Data Species Occurrence Data and Range Maps Choosing Which Habitats to Address Weighted-Additive Model Data Normalization Ranking Weighted-Additive Model Viewer Application ACE-II Evaluation References Tables and Figures Table 1. Uses and limitations of ACE-II Data disclaimer Figure 1. ACE-II Biological Index Model Flow Chart...Error! Bookmark not defined. Table 2. ACE-II recreational needs and opportunities Table 3. Types of areas of high conservation value not addressed in ACE-II, and datasets available to identify these areas Appendices Appendix A. Table of conservation priorities and how they are addressed in ACE-II... A-1 Appendix B. Data needs, layer wish list, and tasks for ACE-III and beyond... B-1 Appendix C. List of species included in richness counts...c-1 Appendix D. List of rare species included in rare species richness and rarity-weighted richness...d-1 ACE-II Project Report 3

4 Executive Summary The mission of the Department of Fish and Game (Department) is unique in its broad responsibility to conserve California s natural resources for both ecological and recreational values. To meet its responsibilities and comply with specific laws and mandates, the Department must establish programs and processes that will guide and inform its priorities for species and habitat conservation. The goal of the Areas of Conservation Emphasis project (ACE-II) was to build a spatial model that would incorporate Department priorities and mandates, be transparent and repeatable, use the best available science, and be flexible and responsive to specific management questions or funding opportunities. ACE-II is a compilation of statewide, spatial data addressing specific biological and recreational values, stressors, and landscape considerations analyzed at a consistent scale of 2.5 square mile hexagons that can be used in a flexible manner to identify areas of biological or conservation interest. The ACE-II project team developed spatial data layers that depict California s biological diversity and recreational opportunities. The primary focus of ACE-II was to collect and summarize the best available statewide, spatial data on biological richness, including species diversity, rarity, and sensitive habitats. Information on recreational needs and opportunities throughout the state, including fishing, hunting and wildlife-viewing, was also compiled. This information was summarized in maps showing patterns of harvest species richness, hunting demand, recreational access, and hunting use. To depict biological richness, four indices relevant to conservation value were produced: native species richness, rare species richness, irreplaceability (i.e., rarity-weighted richness), and the presence of sensitive habitats. Native richness and rarity layers were developed for each of six taxonomic groups: birds, fish, amphibians, plants, mammals, and reptiles. The data were then combined across taxonomic groups to produce total native species richness, total rare species richness, and total rarity-weighted richness maps. These maps are normalized to give each taxonomic group equal weight, to remove any bias caused by the variation in the total number of taxa per taxonomic group. The layers produced can be used to view the distribution of richness and rarity, by individual taxonomic group and overall, throughout the state and within each USDA ecoregion section. Information on the location of four sensitive habitat types, wetlands, riparian, rare upland natural communities, and high value salmonid habitat, was also assembled. The sensitive habitat layers can be used to view the distribution of these habitat types throughout the state based on the best currently available data. The four indices of richness and rarity were combined in a weighted additive model to produce the ACE-II biological index surface. See Figure 1 for further details on the biological index calculation. Hexagons with a high biological index score represent those areas with high species richness, high levels of rarity and irreplaceability, and/or sensitive habitats. The biological index was calculated separately by USDA Ecoregion section, to identify the areas of highest richness and rarity within each ecoregion of the state. Because each ecoregion was analyzed separately, the biological index surface is meant to be viewed only one ecoregion at a time; biological index scores are not directly comparable between ecoregions. ACE-II Project Report 4

5 Areas with a high biological index score would be expected to have high conservation value and meet multiple conservation goals. However, data included in ACE-II are subject to certain assumptions and limitations (summarized in Table 1) that must be considered in any use or application of the data. The biological index surface is limited by the accuracy and scale of the input data, and does not represent all areas of high biological value throughout the state. The ACE-II biological index model is a broad-scale analysis and does not incorporate all biological considerations that should be addressed during comprehensive conservation planning. Therefore, it should not be interpreted as a map of the Department s conservation priorities. Current level of protection, level of habitat conversion (i.e., urbanization), intactness and connectivity, and stressors to natural habitats, all important considerations when determining conservation value, were not considered when developing the biological index. For example, urban areas may have a high biological index score even though they have low conservation value, because urbanization was not a component of the biological index score. The biological index surface is not a delineation of the reserve configuration needed to ensure adequate protection of individual species or habitats. The biological index does not replace site-specific evaluation of biological resources and should not be used as the sole measure of conservation priority during planning. The biological index layer was reviewed by Department staff with local expertise on the distribution of biodiversity and conservation value in the landscape throughout the state. Many areas of high conservation value as identified by local experts received high biological index scores. Areas of high conservation value that received low biological index scores generally fell into the following categories: habitats important for a single focal species, habitats with population-level importance (e.g., largest population, southernmost population), wildlife linkages and corridors, intact wildland areas or areas adjacent to conserved lands, specific upland habitat types such as oak woodland and coastal sage scrub, aquatic reaches and fish habitat, habitats with high invertebrate diversity or rarity, large game important habitat (e.g., deer winter range), and habitats with limited public data such as large tracts of private lands. Products of the ACE-II project include a set of tools for displaying biological and recreational data that can be used to identify areas of potential biological or conservation interest and may be useful during conservation prioritization. The data are available for viewing in an interactive, online ACE-II viewer. The viewer allows the ACE-II biological richness maps, ACE-II recreational demand and opportunities, stressors, protected status of lands, and connectivity and corridors to be overlaid. This viewer tool allows the user to display and contrast the arrangement and relative value of California s unique biological resources, providing a first step toward setting conservation priorities statewide. The viewer also provides a weighted-additive model interface that allows for custom calculation of a biological index using user-defined weights, which is a preliminary step in developing a flexible framework to address specific land acquisition or management questions. ACE-II Project Report 5

6 Background The mission of the Department of Fish and Game (Department) is unique in its broad responsibility to conserve California s natural resources for both ecological and recreational values. To meet its responsibilities and comply with specific laws and mandates, the Department must establish programs and processes that will guide and inform its priorities for species and habitat conservation. A number of other conservation organizations (e.g., The Nature Conservancy, Trust for Public Land) have developed conservation prioritization models that spatially address their priorities. The goal of ACE-II was to build a spatial model that would incorporate Department priorities and mandates, be transparent and repeatable, use the best available science, and be flexible and responsive to specific management questions or funding opportunities. The ACE-II technical team was assembled in April ACE-II is a compilation of statewide spatial data addressing specific biological and recreational values, stressors, and landscape considerations analyzed at a consistent scale of 2.5 square mile hexagons. ACE-II is a tool for use in land acquisition and conservation decision-making. Appropriate use of ACE-II will consider data assumptions and limitations outlined in this report. The purpose of ACE-II was to develop a tool that can be used in a flexible manner to identify areas of biological or conservation interest. It should not be interpreted as a map of conservation priorities. The Role of ACE-II in Conservation Prioritization One purpose of ACE-II was to develop a tool for displaying biological and recreational data that could be used to identify areas of potential biological or conservation interest. This tool may provide information that would be useful during a conservation prioritization, but is not intended for use as a stand-alone tool to delineate conservation priority areas. The process for delineating conservation priority areas is reviewed below. Conservation priority areas can be defined as those areas that should be scheduled for conservation action first, and are generally designed to represent the biodiversity of the region they are situated in (Margules et al. 2002). To date, a number of conservation prioritization efforts have been undertaken across the globe, and have been implemented at varying spatial scale, spatial extent, and in a variety of habitat types (Malczewski et al. 2003, Geneletti 2004, Phua and Minowa 2005, Ricketts and Imhoff 2003, Reyers et al. 2007, Geneletti 2008, Gorokhovich and Voustianiouk 2009). The methods used may vary depending on project goals and resources, but should typically be explicit, efficient, flexible, cost-effective, and make the most of available data. Conservation priority areas generally have the following attributes (adapted from Margules et al. 2002): Are necessary in combination with other areas to achieve conservation targets; Rarely constitute all remaining natural or semi-natural habitat in a region; ACE-II Project Report 6

7 Will never encompass all biodiversity, but rather work toward the goal of encompassing a representation of important biodiversity; Will not sustain their biodiversity over time if managed in isolation; Protection of some areas may be "non-negotiable" if they contain unique components of diversity that cannot be substituted in other areas; Are based on the best current available data, which always have limitations and are never complete. The model can and should be modified later as more data become available. Margules et al. (2002) described the process needed to identify priority areas for conservation as follows: 1) measure diversity or conservation value (using surrogates) 2) set goals, including determining sufficient levels of representation if applicable 3) develop methods to implement goals 4) product should represent each level of biodiversity or conservation value identified 5) prioritize areas using a) complementarity b) irreplaceability c) threat d) sustainability The ACE-II tool provides data for use in step 1 of the above process. Project Goals and Assumptions Department Planning and Conservation Prioritization Goals Based on reviews of the Fish and Game code and acquisition and funding priorities developed by the Wildlife program and the Lands program, the ACE-II technical team developed a list of Department mandates and conservation priorities (Appendix A). High priority conservation areas in California that are needed to fulfill the Department s mission and meet Department mandates include those areas that: a) Best conserve fish and wildlife presence, use and diversity; b) Conserve functional ecosystems; c) Avoid extinctions, extirpations, and the need to list species; d) Provide hunting, fishing, and wildlife observation opportunities for the public; and e) Support climate change adaptation planning. ACE-II Project Report 7

8 Assumptions The ACE-II technical team developed a list of additional biological and spatial assumptions relevant to the identification of high priority conservation areas in California. Many of these assumptions were not addressed in the data layers developed for ACE-II, but should be considered in a comprehensive conservation prioritization. Long-term conservation potential should consider the overall viability of a target occurrence, status of stressors affecting the occurrence, predicted changes in the environment over time, and the conservation management status of the habitat supporting the occurrence. Areas that support multiple species are generally more valuable than those that support single species. Conserving adequate areas of all habitat types in the state will capture the conservation of many species. Large, well-connected preserves provide opportunities for species movement between current and future suitable habitats, accommodate range shifts, and provide habitat and refuge areas to help species persist in a changing climate. Large, well-connected preserves will help maintain and increase ecological integrity and offer increased protection from catastrophic events such as fire or flood. Areas that are intact and less fragmented from housing and roads have higher biological value. Conservation areas that provide connectivity along elevational or latitudinal gradients will improve the ability of species to persist in a changing climate. Conservation of functional ecosystems will improve hunting, fishing, and wildlife observation on and adjacent to conserved lands. Conservation prioritization is limited by the spatial extent and scale of available data. The spatial extent of data layers used must encompass the entire study area. For example, a statewide prioritization will be limited to only those data layers with a statewide or greater spatial extent. The scale chosen should be coarse enough to maximize use of available data but must be fine enough to be meaningful for local planning. ACE-II Objectives The first project objective was to identify and compile currently available data that may be considered in a conservation prioritization model. This was done through a Department-wide call for data, and additional effort by the ACE-II technical team to obtain specific data layers. The inventory and assessment of current data also resulted in the identification of future data needs (Appendix B). To begin addressing the Department s conservation prioritization goals, the ACE-II technical team was tasked with developing the following product(s): A tool for use in identifying areas of the state that may meet broad conservation goals such as areas that have high biodiversity, high recreational value, or high value for ACE-II Project Report 8

9 meeting mandates. A tool that is meant to complement other efforts, such as ACE I (identification of areas based on local expert knowledge), the California Essential Habitat Connectivity project (Spencer et al. 2010), and local conservation plans. A modeling process for spatial assessment of biological richness that is transparent, repeatable, can be modified and used for different purposes using the best currently available biological information, and can be updated and repeated as new data are available. A tool to share the Department s biological data that may be relevant to conservation prioritization with all levels of government, non-profits, and private environmental endeavors. A tool that can be used to create maps of biological richness based on the best current scientific knowledge, to provide guidance to: o and WCB, for use in identifying areas of biological or conservation interest when determining high priority areas for land acquisitions o Other planning efforts (e.g., climate change adaptation planning) A process that can identify future modeling and data needs. ACE-II Data Layer Descriptions, Uses and Limitations ACE-II is a compilation of statewide, spatial data addressing specific biological and recreational values, stressors, and landscape considerations. ACE-II is a tool for use in land acquisition and conservation decision-making. The data included in ACE-II are subject to certain assumptions and limitations, which must be considered in any use or application of the data. The uses and limitations of ACE-II are described below and are summarized in Table 1. Hexagons All ACE-II datasets were applied to a statewide, 2.5 square-mile hexagon grid. The hexagons were clipped to the 24k state boundary, and represent terrestrial California. All marine species and habitats, as well as islands, were excluded from the analysis. Data precision All ACE-II data values are generalized across 2.5 square mile hexagons, and therefore cannot be used to pinpoint specific parcels with high biological richness in the landscape. The ACE-II data values are applied to hexagons that have a consistent size (2.5 square miles) and shape. Hexagon borders do not correspond with political or land ownership boundaries. ACE-II does not identify specific parcels with high conservation value. ACE-II incorporates datasets that vary in accuracy and scale. The precision of ACE-II values is limited by the accuracy and scale of the source data. ACE-II Project Report 9

10 Table 1. Uses and Limitations of ACE-II. ACE-II IS an analysis tool that shows broad-scale patterns of biological richness (defined by biodiversity, rarity, irreplaceability, and presence of sensitive habitats) across the landscape. a continuous surface of biological richness based on data and assumptions outlined in this report. a tool that includes biological layers showing patterns of richness and rarity based on numbers of species potentially present per hexagon. a broad-scale analysis of biological richness based on currently available, statewide data, upon which future analyses can be built. All data were applied to 2.5 square mile (1600 acres) hexagons. a tool displaying biological metrics of biodiversity, rarity, irreplaceability, and the presence of sensitive habitats within a hexagon. a dynamic analysis tool to inform conservation and land acquisition decisions based on specific management questions or project goals. A tool comprised of datasets that will be revised over time as new data become available. an analysis tool to facilitate the identification of areas of biological and conservation interest. ACE-II IS NOT a map of the California Department of Fish and Game s conservation priorities. a hard-line map delineating the reserve configuration needed to meet specific conservation or management goals, such as ensuring adequate protection of individual focal species or habitats. a comprehensive analysis of species-specific habitat needs or critical conservation areas for individual species. a tool that can be used to assess the biological or conservation value of specific parcels. The precision of ACE-II values is limited by the accuracy and scale of source data. The value of any single hexagon should be interpreted with caution. a prioritization tool that incorporates all four facets of a conservation prioritization: complementarity (e.g., current level of protection), irreplaceability, threat, and sustainability (e.g., landscape configuration). a definitive, final map. a regulation or a plan that dictates land use or land acquisition decisions for any public or private entity, nor is it a California Department of Fish and Game response to potential impacts to a habitat or species from a project subject to the California Environmental Quality Act (CEQA), California Endangered Species Act (CESA), National Environmental Policy Act (NEPA) or federal Endangered Species Act (ESA). Data Disclaimer The ACE-II maps display biological and recreational values based on available data and constrained by the limitations of the data. These values do not represent critical conservation areas for individual species or habitats. The values may be influenced by level of survey effort and do not consider current levels of protection for species or habitats. Some areas showing low biological or recreational values may have high conservation value. The ACE-II data represent broad-scale patterns of biological richness, and the value of any single hexagon should be interpreted with caution. ACE-II is a decision-support tool to be used in conjunction with species-specific information and local-scale conservation prioritization analyses. The user accepts sole responsibility for the correct interpretation and use of the ACE-II datasets and report. The ACE-II maps do not replace the need for site-specific evaluation of biological resources and should not be used as the sole measure of conservation priority during planning. No statement or data set shall by itself be considered an official response from a state agency regarding impacts to wildlife resulting from a management action subject to the California Environmental Quality Act (CEQA). ACE-II Project Report 10

11 ACE-II is a compilation of the best available scientific information. However, many of these datasets are not comprehensive across the landscape, may change over time, and should be revised and improved as new data become available. Biological Datasets Native Species Richness Native species richness represents the total number of native taxa potentially present per hexagon based on species range maps, and can be used to view patterns of diversity statewide and ecoregionally. Richness counts for all six taxonomic groups (amphibians, birds, fish, mammals, plants, reptiles) were based on full species only; counts did not consider subspecies or varieties because range maps were generally not available at the subspecific level. See Appendix D for the list of species included in richness counts. Range data are coarse-scale (i.e., the actual distribution of the species may be limited to certain habitat types within the range), which would be expected to result in an overestimate of species richness in some hexagons. Therefore, the native richness values per hexagon represent generalizations of the distribution of diversity throughout the state, but are not meant to represent actual number of species present per hexagon. Native Species Richness was derived from the Department s CWHR native species range maps for amphibians, birds, mammals 1 and reptiles; from the 1998 University of California, Davis fish distribution coverages produced for The Nature Conservancy by Peter Moyle and Paul Randall for fish; and from the Jepson ecoregions designations in Hickman (1993) for plants. Of the 694 species ranges that have been mapped to date in CWHR, 664 are native species, with 660 included in this project (excludes offshore island species). Of the 112 inland fish species ranges by Moyle and Randall, 58 are native. Plant richness was calculated based Jepson ecoregion designations for 4960 native species (excludes subspecies and varieties). For animals except fish, native species richness was calculated per hexagon as the total number of all native species ranges overlapping each hexagon s center point, with separate totals for each taxonomic group: amphibians, birds, mammals, and reptiles. Calculations of richness were based on the hexagon center point rather than by simple presence or absence in the hexagon in order to reduce error along the edges of ecoregional boundaries: Because CWHR species ranges are often snapped to ecoregional boundaries, hexagons along the border between two ecoregions show artificially high richness (i.e., species in both ecoregions overlapping the hexagon are counted, resulting in stripes of high richness along ecoregional boundaries). Using the center-point method eliminated this error. When the center point of a hexagon fell outside the state boundary (i.e., in the ocean or a neighboring state), the richness value was calculated by averaging the values from all adjacent hexagons. Native inland fish species richness was calculated per hexagon as the total number of fish whose ranges overlap >5% of the hexagon area. The center point method was not used for fish due to the linear nature of many aquatic systems; linear habitats may be less likely to intersect a hexagon center point. Native plant species richness was calculated by Jepson Ecoregion. Jepson ecoregion designations of all subspecies were merged, 1 Updated ranges provided by the C Wildlife branch were used for bear, elk and deer instead of CWHR ranges. ACE-II Project Report 11

12 and species counts per ecoregion were based on full species only. To assign plant richness, each hexagon was given the plant richness value of the Jepson ecoregion covering the greatest area within that hexagon. Data for each taxonomic group were normalized separately to give each taxonomic group equal weight (maximum value of 1) in the analysis (see section on data normalization for a detailed description of this process). Statewide normalized values for the six taxonomic groups were summed to determine statewide total native species richness. Ecoregionally normalized values for five taxonomic groups (excluding plants) were summed to determine ecoregional total native richness. Because native plant ranges were available at the ecoregion level only, native plant richness was not normalized ecoregionally, and native plant richness was excluded from the total species richness values normalized by ecoregion. Total native species richness is the sum of richness normalized by taxonomic group 2. Areas with high ACE-II total native species richness represent not only areas with the greatest total count of species, but also areas with high relative richness per taxonomic group. For example, although amphibians may contribute only a small number to the total count of species in a hexagon, areas with high relative amphibian richness would contribute a large relative richness value in the normalized richness calculation. Native species richness by taxonomic group displays the count of native species per hexagon, and can be used to view the distribution of diversity in each taxonomic group by ecoregion or statewide. The list of species potentially present in any hexagon in the state based on species range maps can be obtained using a database query. Rare Species Richness Rare species richness represents the total number of special status 3 taxa present per hexagon based on documented species occurrences, and can be used to view patterns of rarity. Rare species richness counts were conducted for all six taxonomic groups (amphibians, birds, fish, mammals, plants, reptiles) at the taxonomic level treated as special status. See Appendix E for the list of taxa included in rare species richness counts. Rare species occurrence locations were derived from presumed extant California Natural Diversity Database records (excluding extirpated and possibly extirpated records); additional museum records from the California Academy of Sciences, the Museum of Vertebrate Zoology at UC Berkeley, and the Consortium of California Herbaria (from years ); and additional Department datasets (BIOS, other regional or branch data). All documented occurrences with accuracy ±1 mile or better were included in order to incorporate as many known occurrences as possible. No cut-off date of observation was used, based on the assumption that occurrences still may be present if the habitat has not been modified and the 2 The richness values for each taxonomic group were normalized from 0 to 1 before summing to give each taxonomic group equal weight in the analysis (see section on data normalization for detailed description). 3 Special status taxa included all State- and Federally-listed or Candidate species, species of special concern, fully-protected species, and CNPS List 1B and List 2 plants ACE-II Project Report 12

13 occurrences have not been documented as extirpated. Further supporting this assumption are the results of recent survey efforts that successfully relocated decades-old historical occurrences of several species. A 1 mile buffer was added to all occurrence points and polygons to standardize accuracy. All hexagons with >5% area covered by a buffered documented occurrence were considered presences. The total number of rare species was counted per hexagon for each taxonomic group: amphibians, birds, fish, mammals, plants, and reptiles. Data for each taxonomic group were normalized separately to give each taxonomic group equal weight (maximum value of 1) in the analysis (see section on data normalization for a detailed description of this process). Statewide normalized values for the six taxonomic groups were summed to determine statewide total rare species richness. Ecoregionally normalized values for the six taxonomic groups were summed to determine ecoregional total native richness. Verified species occurrences mapped by CNDDB and museum data tend to be spatially biased toward areas with high levels of survey effort, which may result in particularly high rare species richness values in well-surveyed areas. Conversely, surveys have not been conducted in a comprehensive and consistent manner across the entire landscape, and current maps of verified rare species occurrences are expected to have high rates of omission. For this reason, counts of rare species richness would be expected to be underestimates in some hexagons, particularly those for which no survey data are available. A data layer showing those hexagons for which no rare species data are available has been produced and can be used to identify the most poorly surveyed areas. Total rare species richness is the sum of rare species richness normalized by taxonomic group. Data were normalized per taxonomic group to remain consistent with the methods used for total native species richness. Areas with high ACE-II rare species richness represent not only areas with the greatest total count of rare species, but also areas with high relative rare species richness per taxonomic group. Rare species richness by taxonomic group displays the count of rare species per hexagon based on documented occurrences, and can be used to view the distribution of rarity in each taxonomic group by ecoregion or statewide. Rarity-weighted Richness Rarity-weighted richness represents the irreplaceability of an area based on the presence of special status species 4 weighted by their degree of rarity. Areas with a high rarity-weighted richness index (RWI) support rare species with few documented occurrences; these areas would be expected to support unique habitats or suites of species that are limited in distribution and likely of high conservation concern. The RWI was calculated by taking the inverse of the number of hexagons occupied by each rare taxon [RWI = Σ 1/(# occupied hexagons per taxon)], so that taxa with the smallest distributions have the largest values. All RWI values were then summed per hexagon by taxonomic group. Data for each taxonomic group were normalized separately to 4 List of species status species used for rarity-weighted richness was the same as that used for rare species richness. ACE-II Project Report 13

14 give each taxonomic group equal weight (maximum value of 1). Statewide normalized values for the six taxonomic groups were summed to determine statewide total RWI. Ecoregionally normalized values for the six taxonomic groups were summed to determine ecoregional total RWI. Because verified species occurrences were used to determine species distributions for the purposes of this calculation, the RWI may be biased by the level of survey effort for certain species or within certain areas of the state, or by the level of reporting to CNDDB. Rarityweighted richness best represents the irreplaceability of areas supporting narrow-ranging species and habitats. Wide-ranging species that are rare within their range would have low RWI values although they may be of high conservation concern. A separate metric should be used to identify the areas of highest concern for wide-ranging species. Total rarity-weighted richness is the sum of RWI normalized by taxonomic group. Data were normalized per taxonomic group to remain consistent with the methods used for total native species richness and rare species richness. Areas with high ACE-II rarity-weighted richness represent not only areas with the greatest RWI, but also areas with high relative RWI per taxonomic group. Rarity-weighted richness by taxonomic group displays the total RWI per hexagon by taxonomic group, and can be used to view the level of irreplaceability among hexagons by ecoregion or statewide. Sensitive Habitats The ACE-II sensitive habitat layers represent those hexagons where wetlands, riparian, rare natural communities, and/or high value salmonid habitat are present. If a sensitive habitat of any size was mapped as present in a hexagon, the hexagon was designated a presence for that habitat type regardless of habitat size or quality. Sensitive habitats were designated as present or absent only and hexagons were not ranked by any measure of sensitive habitat conservation value. The sensitive habitat layers are therefore very broad-scale representations of the distribution of these habitat types throughout the state. Riparian The riparian habitat layer represents those hexagons in which riparian habitat is present. Most generally, habitats classified as riparian represent streamside vegetation. This includes riparian forest, riparian woodland, riparian scrub and other streamside vegetation types. Riparian data for the state are inconsistent in geographic area coverage and resolution. Various sources therefore contributed to the creation of a statewide riparian coverage for the use of this project. It should be noted that a consistent methodology was not used by the source datasets to identify and classify habitat termed riparian. GIS data input into the riparian statewide layer originated from the following sources: the most current Ca. Dept. of Forestry and Fire Protection s Multi-Source Land Cover Data covering the entire state (30 meter pixel); Ca. Dept. of Water Resources Land Use Survey data for agricultural areas ACE-II Project Report 14

15 (1:24,000 polygons); s Calif. Natural Diversity Database (CNDDB) riparian habitats and associated species occurrences (1:24,000 polygons); and Central Valley wetlands raster grid from Pacific Meridian Resources/Duck s Unlimited (30 meter pixel). Taken together, these sources identify many but not all riparian zones in the state. Therefore the ACE-II statewide riparian layer includes the best available information on riparian habitat statewide, but is not expected to represent all riparian zones in the state. Wetland The wetland habitat layer represents those hexagons in which wetland habitat, generally defined as habitat where the soil is saturated with water either permanently or seasonally, is present. This includes habitats such as estuarine and coastal marshes, tidal flats, freshwater marshes, lakes and ponds, desert springs, seeps, fens, and vernal pools. Permanently and seasonally flooded agricultural lands were denoted but were not classified as wetlands for purposes of the analysis. Wetland data for the state is inconsistent in geographic area coverage and resolution. Various sources contributed to the creation of a statewide wetlands coverage for the use in this project. GIS data input into the wetland statewide layer originated from the following sources: the most current Ca. Dept. of Forestry and Fire Protection s Multi-Source Land Cover Data covering the entire state (30 meter pixel); Ca. Dept. of Water Resources Land Use Survey data for agricultural areas (1:24,000 polygons); US Fish and Wildlife Service National Wetland Inventory maps (1:24,000 polygons); California lakes mapped by (1:24,000 polygons); s Calif. Natural Diversity Database (CNDDB) wetland habitats and associated species occurrences (1:24,000 polygons); Central Valley wetlands raster grid from Pacific Meridian Resources/Duck s Unlimited (30 meter pixel); various county vernal pool coverages; USFS mapped fens and fen meadows in the Sierra Nevada; and local vegetation maps of Marin County and the western Mojave showing wetland vegetation types. Taken together, these sources identify many but not all wetland areas in the state. Therefore the ACE-II statewide wetland layer includes the best available information on wetland habitat statewide, but is not expected to represent all wetland habitats in the state. Rare Natural Communities Rare natural communities included for the purposes of this project were those communities designated as rare by Holland (1986) and mapped in CNDDB (1:24,000 polygons). It should be noted that not all rare natural communities are well-represented in CNDDB. Therefore, the rare natural communities coverage represents areas where rare natural communities are known to occur, but is not a comprehensive representation of rare natural communities across the state. Riparian and wetland rare natural communities were excluded from this coverage since they were included in the riparian and wetland sensitive habitat layers. Additional occurrences of some rare natural communities were added from local vegetation maps. High Value Salmonid Habitat High value salmonid habitat included all COHO, steelhead, and heritage native trout watersheds as mapped by the Department. ACE-II Project Report 15

16 Biological Index The ACE-II biological index surface is a composite of four indices relevant to conservation value: native species richness, rare species richness, irreplaceability (i.e., rarity-weighted richness), and the presence of sensitive habitats (see Figure 1 for further details on biological index calculation). The four indices were summed using a weighted-additive model framework (see the weighted-additive model section for further detail), with all four layers given equal weight in the model. Hexagons with a high biological index score represent those areas with high species richness, high levels of rarity and irreplaceability, and/or sensitive habitats. The statewide layers were summed to produce a Statewide Biological Richness Overview map. This map can be used for comparisons of biological richness between any two areas of the state; however, it does not account for the large ecological differences across different regions of the state and has very limited use for regional or local-scale planning. The Ecoregional Biological Index was calculated separately by USDA Ecoregion section, to identify the areas of highest richness and rarity within each ecoregion of the state. This index accounts for ecological differences across different areas of the state and would be more appropriate for use during regional planning. However, because the index was calculated separately by ecoregion, the biological index scores are not directly comparable between ecoregions. Areas with a high biological index score would be expected to have high conservation value and meet multiple conservation goals. However, data included in ACE-II are subject to certain assumptions and limitations (summarized in Table 1) that must be considered in any use or application of the data. The biological index surface is limited by the accuracy and scale of the input data, and does not represent all areas of high biological value throughout the state. It is a broad-scale analysis and does not incorporate all biological considerations that should be addressed during comprehensive conservation planning. Therefore, it should not be interpreted as a map of the Department s conservation priorities. Current level of protection, level of habitat conversion (i.e., urbanization), intactness and connectivity, and stressors to natural habitats, all important considerations when determining conservation value, were not considered when developing the biological index. For example, urban areas may have a high biological index score even though they have low conservation value, because urbanization was not a component of the biological index score. The biological index surface is not a delineation of the reserve configuration needed to ensure adequate protection of individual species or habitats. The biological index does not replace site-specific evaluation of biological resources and should not be used as the sole measure of conservation priority during planning. ACE-II Project Report 16

17 Figure 1. ACE-II Biological Index Model Flow Chart. The Biological Index is based on four indices relevant to conservation value, native species richness, rare species richness, irreplaceability, and the presence of sensitive habitats, summed in a weighted-additive model framework. Data were normalized to give each taxonomic group and each of the four indices equal weight in the analysis. The analysis was done by ecoregion, to identify areas of high biological richness within each ecoregion of the state. The analysis unit used was 2.5 square mile hexagons. Step 1. Data compilation Dataset Data group Source Process 1 Native Birds CWHR ranges 2 species Amphibians 3 richness Reptiles 4 Mammals 5 Fish Brown & Moyle ranges 6 Plants Jepson Ecoregions based on The Jepson Manual (Hickman 1993). 7 Rarityweighted Birds CNDDB records (excluding extirpated 8 Amphibians records and records with accuracy of 9 richness Reptiles >1 mile) and additional museum 10 index Mammals records. All records were buffered by 11 (RWI) Fish 1 mile to standardize accuracy. 12 Plants 13 Rare Birds 14 Species Amphibians 15 Richness Reptiles 16 Mammals 17 Fish 18 Plants 19 Sensitive Riparian 20 habitats Wetlands 21 Rare natural communities 22 High value salmonid habitat Habitat mapped by Calveg, CNDDB, DWR, NWI, some local maps. CNDDB mapped rare natural communities excluding riparian and wetland habitats. Additional rare natural communities from local vegetation maps were also added. COHO, steelhead, and heritage native trout watersheds. Count of number of native species per hexagon based on range maps. [RWI=Σ 1/(# hexagons occupied per species)] Based on occurrence data. The species found in the fewest number of hexagons have the highest values. Count of number of rare species per hexagon based on occurrence data. All hexagons with a mapped location of the habitat type marked as presences (0=not present; 1=present). Step 2. Model development A. Normalize data layers 1-22 from 0-1 by ecoregion. B. Sum normalized data layers in each of 4 dataset categories to obtain the four final data layers. C. Normalize the 4 final data layers from 0-1 by ecoregion. D. Sum the normalized final data layers to calculate the biological index. Note: Each layer was normalized ecoregionally, meaning the data values in each layer were scaled from 0-1 based on all values within the ecoregion. Normalizing by taxonomic group removed any potential bias caused by differences in the number of taxa per taxonomic group. Normalization of the four final data layers was done to standardize the weights of the data values input into the weighted-additive model. ACE-II Project Report 17

18 Recreational Datasets The ACE-II recreational data include maps of harvest species richness, recreational access opportunities, hunting demand and hunting use, summarized in Table 2. These maps provide coarse-scale representations of specific recreational needs and opportunities statewide. Incorporating recreational needs into a conservation prioritization will require a more focused analysis of harvest species habitat needs and recreational demand. Harvest Species Richness Harvest Species Richness represents the total number of harvest species (i.e., species that can be hunted, angled, or trapped according to the Fish and Game code) per hexagon. It was derived from the Department s CWHR harvest species range maps for amphibians, birds, and mammals 5, and from the 1998 University of California, Davis fish distribution coverages produced for The Nature Conservancy by Peter Moyle and Paul Randall for fish. Harvest species may be native or non-native. Of the 694 species ranges that have been mapped to date in CWHR, 86 are harvest species: 1 amphibian, 51 birds, and 34 mammals. Of the 112 inland fish species ranges by Moyle and Randall, 52 are harvest species. For animals except fish, harvest species richness was calculated per hexagon as the total number of all harvest species ranges overlapping each hexagon s center point, with separate totals for each of the taxonomic groups. Calculations of richness were based on the hexagon center point rather than by simple presence or absence in the hexagon in order to reduce error along the edges of ecoregional boundaries: Because CWHR species ranges are often snapped to ecoregional boundaries, hexagons along the border between two ecoregions show artificially high richness (i.e., species in both ecoregions overlapping the hexagon are counted, resulting in stripes of high richness along ecoregional boundaries). Using the center-point method eliminated this error. When the center point of a hexagon fell outside the state boundary (i.e., in the ocean or a neighboring state), the richness value was calculated by averaging the values from all adjacent hexagons. Harvest inland fish species richness was calculated per hexagon as the total number of fish whose ranges overlap >5% of the hexagon area. The center point method was not used for fish due to the linear nature of many aquatic systems; linear habitats may be less likely to intersect a hexagon center point. Harvest species richness represents raw totals of harvest species; data were not normalized by taxonomic group. Hunting Demand Deer Tag Demand Deer Tag Demand is an index of demand for deer tags per deer hunt zone across the state. It represents percent success for obtaining the tag of choice [# of tags available / # of tag applications] per deer hunt zone in California. Data from several years are presented, along with an average across these years. For zones in which there is a drawing for tags and there 5 Updated ranges provided by the C Wildlife branch were used for bear, elk and deer instead of CWHR ranges. ACE-II Project Report 18

19 are fewer tags available than applicants, percent success may be <1, or less than 100% success. For zones in which there is no drawing and tags are unavailable after a quota is filled, success does not drop below 1, or 100%, because there are no data for how many additional tags were desired. For zones in which there were fewer applicants than available tags, percent success is shown as >1. Waterfowl Hunt Demand Waterfowl Hunt Demand represents applicant success for reservations on state and federal waterfowl hunting areas as a measure of hunting demand for waterfowl [# available hunting spots / # of applicants]. Data are presented by Central Valley Habitat Joint Venture Basin for the Central Valley and by USDA Ecological Subsection for other portions of the state. Data from several years are presented, along with an average across these years. Recreational Access Percent Huntable Public Lands Percent Huntable Public Lands represents the percentage of area per county of public lands that allow hunting. Huntable public lands included all Wildlife Areas, National Forest Lands, BLM Lands, and a subset of military lands (Camp Roberts, Fort Hunter Liggett), Ecological Reserves (Dales Lake, Cosumnes River, North Table Mountain, Bair Island, Eden Landing, Tomales Bay, Carrizo Plains, Elkhorn Slough, Kerman, Panoche Hills, Pleasant Valley, San Joaquin River, Stone Corral, Coal Canyon, Baldwin Lake, By Day Creek, Estelle Mountain, Fish Slough, Indian Joe, Oasis spring, Piute Creek, River Springs Lake, Saline Valley, San Felipe Creek, West Mojave, Desert Creek) and National Wildlife Refuges (Clear Lake, Colusa, Delevan, Don Edwards SF Bay, Havasu, Humboldt Bay, Kern, Lower Klamath, Merced, Modoc, Sacramento, Salinas River, Salton Sea, San Luis, San Pablo Bay, Sonny Bono Salton Sea, Sutter, Tule Lake, Willow Creek-Lurline). Hunting may also be possible on some private lands, but these areas may not be readily accessible to the general public so were not included here. The area of public lands that allow hunting was calculated and intersected with a county coverage to find percentage of public huntable lands per county. Fishing Opportunity Locations Fishing Opportunity Locations represent those hexagons with documented fishing access or opportunity. These were derived from a number of spatial data sets: Fishing Access sites, Fishing Piers, and Wildlife Areas and Ecological Reserves that allow fishing; sites named in the Online Fishing Guide; and, stocked waters described in 's Statewide Hatchery Database. Wildlife Viewing Opportunity Locations Wildlife Viewing Opportunity Locations represent public lands that may provide wildlife viewing opportunities. It was derived from a number of spatial data sets: Wildlife Areas and Ecological Reserves; all State Parks, US National Park Service, US Forest Service, US Fish and Wildlife Service, and US Bureau of Land Management lands; and, all Watchable Wildlife sites named but not already included in the public lands data sets. ACE-II Project Report 19